Package it.unimi.dsi.fastutil.shorts

Class ShortArrayFIFOQueue

java.lang.Object
it.unimi.dsi.fastutil.shorts.ShortArrayFIFOQueue
All Implemented Interfaces:
PriorityQueue<java.lang.Short>, ShortPriorityQueue, java.io.Serializable
public class ShortArrayFIFOQueue
extends java.lang.Object
implements ShortPriorityQueue, java.io.Serializable
A type-specific array-based FIFO queue, supporting also deque operations.

Instances of this class represent a FIFO queue using a backing array in a circular way. The array is enlarged and shrunk as needed. You can use the trim() method to reduce its memory usage, if necessary.

This class provides additional methods that implement a deque (double-ended queue).

See Also:
Serialized Form

  • Field Summary

    Fields
    Modifier and Type Field Description
    static int INITIAL_CAPACITY
    The standard initial capacity of a queue.

  • Constructor Summary

    Constructors
    Constructor Description
    ShortArrayFIFOQueue()
    Creates a new empty queue with standard initial capacity.
    ShortArrayFIFOQueue​(int capacity)
    Creates a new empty queue with given capacity.

  • Method Summary

    Modifier and Type Method Description
    void clear()
    Removes all elements from this queue.
    ShortComparator comparator()
    Returns the comparator associated with this priority queue, or null if it uses its elements' natural ordering.
    short dequeueLastShort()
    Dequeues the last element from the queue.
    short dequeueShort()
    Dequeues the first element from the queue.
    void enqueue​(short x)
    Enqueues a new element.
    void enqueueFirst​(short x)
    Enqueues a new element as the first element (in dequeuing order) of the queue.
    short firstShort()
    Returns the first element of the queue.
    short lastShort()
    Returns the last element of the queue, that is, the element the would be dequeued last (optional operation).
    int size()
    Returns the number of elements in this queue.
    void trim()
    Trims the queue to the smallest possible size.

    Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    Methods inherited from interface it.unimi.dsi.fastutil.PriorityQueue

    changed, isEmpty

    Methods inherited from interface it.unimi.dsi.fastutil.shorts.ShortPriorityQueue

    dequeue, enqueue, first, last

  • Field Details

    • INITIAL_CAPACITY

      public static final int INITIAL_CAPACITY
      The standard initial capacity of a queue.
      See Also:
      Constant Field Values

  • Constructor Details

    • ShortArrayFIFOQueue

      public ShortArrayFIFOQueue​(int capacity)
      Creates a new empty queue with given capacity.
      Parameters:
      capacity - the initial capacity of this queue.

    • ShortArrayFIFOQueue

      public ShortArrayFIFOQueue()
      Creates a new empty queue with standard initial capacity.

  • Method Details

    • comparator

      public ShortComparator comparator()
      Returns the comparator associated with this priority queue, or null if it uses its elements' natural ordering.
      Specified by:
      comparator in interface PriorityQueue<java.lang.Short>
      Specified by:
      comparator in interface ShortPriorityQueue
      Returns:
      the comparator associated with this priority queue.
      See Also:
      PriorityQueue.comparator()
      Implementation Specification:
      This implementation returns null (FIFO queues have no comparator).

    • dequeueShort

      public short dequeueShort()
      Description copied from interface: ShortPriorityQueue
      Dequeues the first element from the queue.
      Specified by:
      dequeueShort in interface ShortPriorityQueue
      Returns:
      the dequeued element.
      See Also:
      ShortPriorityQueue.dequeue()

    • dequeueLastShort

      public short dequeueLastShort()
      Dequeues the last element from the queue.
      Returns:
      the dequeued element.
      Throws:
      java.util.NoSuchElementException - if the queue is empty.

    • enqueue

      public void enqueue​(short x)
      Description copied from interface: ShortPriorityQueue
      Enqueues a new element.
      Specified by:
      enqueue in interface ShortPriorityQueue
      Parameters:
      x - the element to enqueue.
      See Also:
      PriorityQueue.enqueue(Object)

    • enqueueFirst

      public void enqueueFirst​(short x)
      Enqueues a new element as the first element (in dequeuing order) of the queue.
      Parameters:
      x - the element to enqueue.

    • firstShort

      public short firstShort()
      Description copied from interface: ShortPriorityQueue
      Returns the first element of the queue.
      Specified by:
      firstShort in interface ShortPriorityQueue
      Returns:
      the first element.
      See Also:
      ShortPriorityQueue.first()

    • lastShort

      public short lastShort()
      Description copied from interface: ShortPriorityQueue
      Returns the last element of the queue, that is, the element the would be dequeued last (optional operation).

      This default implementation just throws an UnsupportedOperationException.

      Specified by:
      lastShort in interface ShortPriorityQueue
      Returns:
      the last element.
      See Also:
      ShortPriorityQueue.last()

    • clear

      public void clear()
      Description copied from interface: PriorityQueue
      Removes all elements from this queue.
      Specified by:
      clear in interface PriorityQueue<java.lang.Short>

    • trim

      public void trim()
      Trims the queue to the smallest possible size.

    • size

      public int size()
      Description copied from interface: PriorityQueue
      Returns the number of elements in this queue.
      Specified by:
      size in interface PriorityQueue<java.lang.Short>
      Returns:
      the number of elements in this queue.